Meðferð lífkviku (VPT) er ætlað að viðhalda varnarvirkni kviku og koma í veg fyrir kvikunám og rótfyllingu, en slíkar aðgerðir eru tæknilega krefjandi og skila ekki alltaf tilætluðum árangri. Evrópsku tannholsfræðasamtökin (ESE) hafa gefið út álitsgerð varðandi meðferð lífkviku í tönnum með djúpa tannátu sem fylgir að einhverju leyti gildandi leiðbeiningum á Norðurlöndum. Ekki hefur tekist að leysa að fullu hvernig meta skuli ástand kviku í tönnum með djúpa tannátu. Meðan tannáta hefur ekki náð í kviku er mælt með að beita meðferð sem opnar ekki inn á kvikuna, s.s. þrepaskiptri fjarlægingu tannátu. Hins vegar eru ráðleggingar Evrópsku tannholsfræðasamtakanna og leiðbeiningar á Norðurlöndum ekki samhljóða þegar tannáta nær niður í kviku. Það má líklega rekja til þess að ekki hefur verið unnt að staðfesta gagnsemi einnar meðferðar umfram aðrar og til erfiðleika við að meta hvenær óafturkræfur skaði hefur orðið á óvarinni kviku. Nýleg kalsíumsilíkatsement sem harðna í snertingu við vökva (vatnsherðanleg) og krefjast lágmarks inngrips kunna að gagnast til meðferðar lífkviku án þess að koma þurfi til meðferðar rótarganga. Framþróun er í meðferð lífkviku og breytinga er vænst á klínískum ráðleggingum

AIM: To evaluate the 10-year survival rate of root filled teeth treated by general dental practitioners (GDPs), and to identify possible prognostic factors.

METHODOLOGY: In 2006, 3 676 individuals had at least one tooth root filled by a GDP within the Norrbotten Public Dental Service, Sweden. Over the next 10 years, 331 individuals died and were excluded. A random sample of 302 of the remaining individuals were included in the study, of whom 280 (n=280 teeth) were included in the analysis. Dental records were reviewed retrospectively by a calibrated researcher to collect predetermined data regarding individual, preoperative, intra-operative, and postoperative factors. The outcome measure was tooth extraction over time, and cases with no events were censored, regardless of apical status or symptoms, until last known date of tooth survival. In case of missing data, individuals were recalled for a control visit. Kaplan-Meier survival tables, and Cox regression models were used for analysis. P<0.05 was considered statistically significant.

RESULTS: The cumulative 10-year survival was 81.7% (standard error: 2.6%), and the mean incidence of tooth extraction during the 10 years was 1.8% per year. The univariate analysis identified three possible prognostic factors (p<0.05) that were associated with extraction: molars, two or more emergency inter-appointment visits during the treatment, and root canal treatments consisting of five or more separate sessions. A multivariate regression analysis revealed no significant relationships for the variables gender, tooth type, number of contacts, any emergency visits during endodontic treatment, number of sessions to complete endodontic treatment, pulp diagnosis, or type of permanent restoration and extraction.

CONCLUSIONS: The mean incidence of tooth loss over the first 10 years after completion of root canal treatment performed by a GDP was approximately 2% per year. No prognostic factors could be identified.

Computed tomography has been used in dentistry as a complement to two-dimensional (2D) imaging since the 1980s. The advent of cone beam computed tomography (CBCT), a more modern computed tomog-raphy technique, meant a revolution in dento-maxillofacial imaging due to sharper images, with less radiation and at a lower cost than with mul-ti-slice computed tomography (MSCT), i.e., conventional medical com-puted tomography. However, CBCT still uses higher radiation doses and is more expensive for the patient than conventional 2D methods. CBCT is generally reported as more accurate than intra-oral radiographs to diagnose pathologies orconditions of interest in endodontics. The diagnostic process is, nevertheless, not only about radiographs and it is not certain that the use of CBCT will provide a different chain of actions, and ultimately result in a health benefit for the patient. There is thus a need to establish whether the added information of computed tomography has an impact on diagnosis and therapy choice in endodontics. Guidelines based on the best available evidence have been issued to as-sist clinicians in how to use CBCT. However, little is known about the decision process that drives dentists to request computed tomography and there is a need for more insight into this process. The aims of this thesis were to assess the influence of CBCT in diagno-ses and treatments choices and to gain insight into dentists’ decision process when requesting CBCT examinations. Study I Cases used were of a fictive standardised clinical history of asympto-matic root-filled maxillary molars from 34 consecutively included pa-tients in which MSCT and intra-oral radiographs taken simultaneously. All cases were analysed by five decision makers. Before and after MSCT assessments were 1-3 months apart. The results showed that MSCT does not improve therapy planning agreement among decision makers but it influences therapy changes within each decision maker, often to more aggressive therapies (e.g. more teeth extractions) Studies II and III The studies were prospective observational studies. The cases were au-thentic clinical scenarios presented to the decision makers who also were the actual caregivers. The same cases were used in both studies II and III involving 53 consecutive patients referred for CBCT using the the evidence based European Commission (EC) guidelines. Seven deci-sion makers in two different clinics participated and made before and after CBCT assessments during normal clinical praxis. The results showed that CBCT significantly influenced changes in diagnoses and therapy plans. The changes in therapies were often towards more ag-gressive therapies and are strongly correlated with changes in diagnoses. CBCT also improved statistically decision makers’ confidence in the assessments. The decision makers felt that CBCT had a positive impact on the patient’s health in a large number of patients, but this could not be controlled, and the assessment was not blinded. Study IV Fourteen strategically selected dentists (informants) that use CBCT for endodontic purposes were interviewed. The interviews were semi-structured. The informants narrated on their last three self-reported CBCT cases. The interviews’ transcripts were analysed by qualitative content analysis. The interpretation of the phenomenon of the decision of using CBCT examinations for endodontic purposes was made at two different levels: the explicit and the implicit content. The explicit con-tent revealed three categories as follows: “visualization as a desire”, “fa-cilitating tough decisions” and “allocation of responsibility”. The im-plict content was interpreted as: dentists working in Sweden seemed to have a clinical common sense that compensates for the unfamiliarity of the guidelines. On the other hand, a “safer than sorry” attitude counter-balanced (e.g when tackling difficult patients) the restriction induced by the common sense approach. There was a belief that the national regula-tory system worked as a gate-keeper for over usage.

Aim: This historical prospective cohort study of the adult population of Sweden is based on data from a national registry: the primary aim was to evaluate the long-term survival of teeth after periradicular surgery. A secondary aim was to identify factors predictive of extraction within 10 years of registration of periradicular surgery.

Methodology: The cohort consisted of all individuals who had undergone periradicular surgery to treat apical periodontitis, as reported to the Swedish Social Insurance Agency (SSIA) during 2009. The cohort was followed until December 31, 2020. Subsequent registrations of extractions were collected for Kaplan-Meier survival analyses and survival tables. The patients' sex, age, dental service provider and tooth group were also retrieved from SSIA. Only one tooth per individual was included in the analyses. Multivariable regression analysis was used and P < 0.05 was considered statistically significant. The reporting guidelines STROBE and PROBE were followed.

Results: After data cleaning, and exclusion of 157 teeth, 5 622 teeth/individuals remained for analysis. The mean age of the individuals at the time of the periradicular surgery was 60.5 years (range 20-97, standard deviation 13.31); 55% were women. At the end of the follow-up, that is, up to 12 years, a total of 34.1% of the teeth had been reported as extracted. The multivariate logistic regression analysis, based on follow-up data at 10 years after registration of the periradicular surgery, included 5 548 teeth, of which 1 461 (26.3%) had been extracted. Significant associations between the independent variables tooth group and dental care setting (both P < 0.001) and the dependent variable extraction were found. The highest odds ratio (OR) for extraction applied to tooth group: compared to maxillary incisors and canines, mandibular molars were at greatest risk of extraction (OR 2.429, confidence interval 1.975-2.987, P < 0.001).

Conclusions: After periradicular surgery in predominantly elderly people in Sweden, approximately three quarters of the teeth are retained over a 10-year period. The type of tooth is associated with extraction: mandibular molars are at greater risk of extraction than maxillary incisors and canines.

Aim: To study the circumstances preceding the CBCT examination referral for endodontic reasons in Sweden. Methodology: Fourteen dentists (8 female) 33–58 years of age (mean =44), practicing in Sweden were strategically selected. Ten of the dentists were specialists in endodontics. The absolute inclusion criterion was experience of referring patients for CBCT for endodontic reasons. The included dentists provided a variation concerning gender, age, work experience, education background, location of practice, service affiliation and accessibility to CBCT. Data was obtained through thematic, semi-structured interviews exposing the context of their last self-reported three referrals. Dentists were encouraged to describe their experiences of the circumstances in their own words, aided by the interviewer’s openended questions. The interviews were audio recorded and transcribed verbatim. Qualitative content analysis was used to analyze the text. Results: The preliminary results may indicate that high clinical diagnostic standards, clinical common sense and a willingness of helping the patient with minimal harm may restrict the use of CBCT to address complex diagnostic judgements or therapeutic decisions, which comply with existing European guidelines on the use of CBCT in endodontics. Knowledge of guidelines was however limited among the interviewed dentists. Conclusions: Common sense and high professional standards seem to lead dentists in Sweden to comply with current European guidelines for the use of CBCT in endodontics even when the den tists lack knowledge of the guidelines. Acknowledgements: This work is funded by the Norrbotten County Council.

Aim: To gain insight into the decision processes of dentists when requesting a cone beam computed tomography (CBCT) examination in endodontic settings. Methodology: Fourteen dentists (eight female) 33–58 years of age (mean = 44) practising in Sweden were interviewed. Ten of the dentists were specialists in Endodontics. The absolute inclusion criterion was experience of referring patients for CBCT for endodontic reasons. The included dentists comprised a strategically selected diverse sample in terms of gender, age, work experience, educational background, location of practice, service affiliation and accessibility to CBCT. Data were obtained through semistructured interviews exposing the context of their last three self‐reported referrals. Dentists were encouraged to describe their experiences of the circumstances in their own words, aided by the interviewer's open‐ended questions. The interviews were audio‐recorded and transcribed verbatim. The text was analysed by qualitative content analysis. Results: The manifest content was organized into three categories that were defined as visualization as a desire, facilitating tough decisions and allocating responsibility. Conclusion: An overall theme (covering the latent content) was identified: A balance between clinical common sense and a ‘better safe than sorry’ attitude guides the use of CBCT in endodontic settings. Informants had high clinical standards, knowledge concerning radiation risks and good sense, which could compensate for their lack of knowledge of guidelines. The national radiation regulatory system was perceived to work as a slightly porous gatekeeper for over‐usage.

OBJECTIVES: The aims of this study were to evaluate whether the use of CT facilitates agreement among endodontists in selecting treatments for root-filled maxillary molars with apical periodontitis and to assess the efficacy of CT in choosing a treatment for such teeth. METHODS: 39 root-filled maxillary molars from 34 patients with suspected apical periodontitis were independently evaluated by 4 endodontists and 1 postgraduate student (decision-makers). Treatment decisions were made based on intra-oral radiographs and a fictive clinical history. After 1-3 months, the same decision-makers repeated the examination of the same teeth but with additional information from a CT examination. Agreement between decision-makers with or without the availability of the CT results was measured with Cohen's kappa coefficient. Differences in selected treatments with or without accessibility to the CT results were plotted for the same endodontists using descriptive statistics. RESULTS: The agreement in assessments among endodontists was slight or fair before the CT results were available (range: 0.081-0.535). No increase was observed after reviewing the CT results (range: 0.116-0.379). After the use of CT, the treatment plan was changed 38-76% of the time by all decision-makers, and the changes affected 57.8% of the cases in the study. CONCLUSIONS: The endodontists in this study exhibited a low degree of agreement when choosing a treatment for root-filled maxillary molars with apical periodontitis. A CT examination of the investigated teeth did not result in a significantly higher degree of agreement, and CT frequently contributed to a shift in the selected therapy.

Aim To determine if Cone Beam Computed Tomography (CBCT) used in accordance with the European Commission guidelines has an impact on the diagnostic thinking confidence and therapeutic decision confidence in a population referred for endodontic problems. Methodology The study includes data collected from October 2011 until December 2012. From two different endodontic clinics consecutive patients were referred to a CBCT examination using criteria in accordance with the European Commission guidelines. The CBCT examinations were performed with similar equipment and standardized between clinics. After a thorough clinical examination and before CBCT examination, the endodontist scored the confidence for both diagnosis and therapeutic decision on a 100 mm visual analogue scale (VAS). After the CBCT examination both diagnosis and therapy plan were revised by the same dentist and a new VAS-score of confidence was performed. The VAS-scores before and after the CBCT examination were plotted for all teeth. Before and after assessments were analyzed with paired samples t-test. Results Fifty-seven patients were referred for a CBCT examination, representing 4% of all patients examined by both endodontic clinics during the study period. Four patients were excluded from the analysis as the protocol was not followed. The final data included 53 patients, and 81 teeth. For all teeth the mean score for diagnostic confidence before CBCT examination was 63 mm (SD 30). After CBCT-examination, the mean of the changes in diagnostic confidence for each patient was 23 mm (SD 27) (P < 0.01). The mean therapeutic decision confidence score Before CBCT was 67 mm (SD 25). The mean of the changes in therapeutic decision confidence after CBCT was 22 mm (SD 28) P < 0.01. Conclusions CBCT examination used in accordance with the European Commission guidelines increased the clinician’s confidence in both diagnostic thinking and therapeutic decision in a population with endodontic problems.

OBJECTIVES: The aim was to assess to what extent cone beam CT (CBCT) used in accordance with current European Commission guidelines in a normal clinical setting has an impact on therapeutic decisions in a population referred for endodontic problems. METHODS: The study includes data of consecutively examined patients collected from October 2011 to December 2012. From 2 different endodontic specialist clinics, 57 patients were referred for a CBCT examination using criteria in accordance with current European guidelines. The CBCT examinations were performed using similar equipment and standardized among clinics. After a thorough clinical examination, but before CBCT, the examiner made a preliminary therapy plan which was recorded. After the CBCT examination, the same examiner made a new therapy plan. Therapy plans both before and after the CBCT examination were plotted for 53 patients and 81 teeth. As four patients had incomplete protocols, they were not included in the final analysis. RESULTS: 4% of the patients referred to endodontic clinics during the study period were examined with CBCT. The most frequent reason for referral to CBCT examination was to differentiate pathology from normal anatomy, this was the case in 24 patients (45% of the cases). The primary outcome was therapy plan changes that could be attributed to CBCT examination. There were changes in 28 patients (53%). CONCLUSIONS: CBCT has a significant impact on therapeutic decision efficacy in endodontics when used in concordance with the current European Commission guidelines.

AIM: To determine whether the outcome of cone beam computed tomography (CBCT) examinations performed in accordance with the European Commission guidelines in a clinical setting has an impact on choosing diagnoses in endodontics. METHODOLOGY: A prospective observational study was conducted. Fifty-three consecutive patients (81 teeth) from two different endodontic specialist clinics in Sweden were followed. After performing a thorough clinical examination (based on the history, clinical findings, and diagnostic tests such as intra-oral radiography), the examiner wrote down a preliminary diagnosis before CBCT examination. After the CBCT examination, a new diagnosis was made by the same examiner. Both the pre- and the post-CBCT examination diagnoses were plotted according to patients and teeth. The CBCT examinations were performed using similar equipment and protocols that were standardized amongst the clinics. RESULTS: The diagnoses were changed for at least one tooth in 22 patients (41%); overall, the diagnoses were changed for 28 teeth (35%). CONCLUSION: CBCT has a substantial impact on diagnostic thinking in endodontics when used in accordance with the European Commission guidelines.